text: The DDB is a collection of experimental data published by the original authors. All data are referenced and a quite large literature data bank is part of the DDB, currently containing more than 92,000 articles, books, private communications, deposited documents from Russia (VINITI), the Ukraine (Ukrniiti) and other former USSR states, company reports (mainly from former GDR companies), theses, patents, and conference contributions.
  Secondary sources like data collections are normally neglected and only used as a literature source. Derived data are also not collected with the main exception of the azeotropic data bank which is built partly from evaluated vapor–liquid equilibrium data.